Electronic apparatus such as a mobile phone, PHS (Personal Handyphone System) and PDA (Personal Data Assistance) having a touch panel on a display unit and works when a user touches a desired position of the touch panel are widely used today.
Such electronic apparatus increasingly have a large-sized screen. A display unit in an electronic apparatus consumes a large amount of power among devices in the electronic apparatus, and the trend toward a large-sized screen results in a further increase in power consumption.
The mobile phone disclosed in Patent Literature 1 has a structure in which the border between a region to be illuminated and a region to be not illuminated is determined when a user continuously touches a touch panel, moving a finger along the border.
Further, the mobile phone disclosed in Patent Literature 2 has a structure in which an operation key to control on and off of illumination of first and second display regions is pressed through a touch panel.